This invention relates generally to fuel vaporization and more particularly has reference to an apparatus and method for supplying fully vaporized air-fuel mixtures to the intake manifold of an internal combustion engine.
Pertinent U.S. and foreign patents are found in Class 123, subclasses 543, 545, 548 and 586; Class 241, subclass 145, and Class 261, subclass 144, of the Official Classifications of Patents in the U.S. Patent and Trademark Office.
Examples of pertinent patents are U.S. Pat. Nos. 2,232,748; 3,496,919; 3,762,385; 3,780,714; 4,068,638; 4,192,270 and 4,212,274.
U.S. Pat. No. 2,232,784 discloses a device for supplying auxiliary air into the carburetor system of an internal combustion engine. The device has automatic control means for varying the amount of air supplied at various throttle openings.
U.S. Pat. No. 3,496,919 discloses a carburetor for delivering fuel from a fuel tank to an engine combustion chamber in vaporized form. A vaporizing chamber has an inlet and an outlet and internal surfaces in contact with a heat exchanger. The heat exchanger is connected to the exhaust gas conduit of the engine. In the vaporizing chamber, the fuel mixture progresses upwardly in a sinuous flow in heat exchange relation with surfaces heated by the exhaust gases of the engine which are conducted from the exhaust of the engine through a conduit into a heat intake passage extending lengthwise of the chamber.
U.S. Pat. No. 3,762,385 discloses an air-fuel pre-heater for an internal combustion engine wherein a water-jacketed fuel vaporizing chamber is interposed between the carburetor and the intake manifold. The flow path in the chamber is tortuous and of considerable length which induces some turbulence and insures vaporization of the gasoline.
U.S. Pat. No. 3,780,714 discloses a fuel vaporizer for internal combustion engines in which a tubing is tightly coiled in a frusto-conical shape and is vertically installed within the intake manifold chamber below and in common mounting arrangement with a conventional carburetor for pre-heating and vaporizing the liquid fuel emitted from the throat of the carburetor. The coiled tubing has opposing open ends that are connected to the water cooling system of the engine and function as inlet and outlet ends for the thermostatically controlled passage of hot water through the coils.
U.S. Pat. No. 4,068,638 discloses a method and apparatus for increasing the vaporized proportion of a stream of volatile liquid fuel supplied to an internal combustion engine. The non-volatized portions of the fuel discharged from the carburetor are traveled over a plurality of flow surfaces, such as the surfaces of a layer of metal balls and the like. In addition, a coil of tubing is also preferably provided with one end arranged to receive fresh air heated by the exhaust manifold of the engine and with the other end downwardly directed from the layer of balls to the intake manifold.
U S. Pat. No. 4,192,270 discloses a fuel system for an internal combustion engine in which an air-gasoline mixture from the carburetor is fed through a plurality of chambers and through a plurality of curved, horizontally positioned, heated tubes which output the mixture to the intake manifold of the engine.
U.S. Pat. No. 4,212,274 discloses a carbonation enhancer having a cylindrical shell that is closed at one end by an envolute wall spaced from the inner end of a withdrawal tube. The output stream of a conventional carburetor is directed tangentially into space between the shells and caused to move in a spiral path toward the envolute enclosure wall by a spiral vane in the space, and on reaching the envolute wall to move radially inwardly and into the inner end of the withdrawal tube to travel axially in a direction opposite the spiral path with the stream exiting the tube to enter the inlet manifold of the engine. Waste engine heat is applied to the exterior of the cylindrical shell in an amount sufficient to vaporize liquid fuel droplets centrifuged thereagainst from the stream as the latter traverses the spiral path portion of its travel from the carburetor to the intake manifold.
Gasoline as a liquid does not burn. Conventional carburetors spray the gasoline into an inducted air stream. The spray is not completely vaporized before combustion.
Many attempts have been made to fully vaporize the fuel in the air stream. Most of these attempts provided means for heating the fuel in the carburetor, resulting in so-called high mileage carburetors. Such devices are undesirable because they require replacement or modification of the conventional carburetor provided as standard equipment on the automobile.
Other attempts to fully vaporize the fuel in the air stream have been unsuccessful because of poor performance and undue complexity.